1. Field of the Invention
The present invention relates to a device for producing a pattern. In particular, the present invention relates to a device which employs an electromagnetic forming process for shaping a work piece.
2. Description of the Related Art
U.S. Pat. No. 7,076,981 discloses a method of forming a bipolar plate through an electromagnetic formation process. The coil in the patent can generate only a single directional magnetic field. Therefore, it is not a suitable method for forming patterns on the sidewalls of a three dimensional metal shell.
Most fine patterns on the metallic surfaces of cell phones are formed through laser engraving, etching or heat transfer printing. A plastic injection manufacturing process is used when a pattern is required to be formed directly onto the casing (as in Taiwan Pat. No. 00544077). However, the pattern produced through this method is of a plastic material and has a low texture quality.
Taiwan Pat. No. 00589929 discloses a manufacturing process and a structure of a metal casing comprising color patterns. The color patterns are first completed on an overlay-film, and the overlay-film is then sintered with the surface of a metal plate through heating. The metal plate is then applied to a metal casing by a pressing process. This is an intricate manufacturing process, and residual stress may be produced during the pressing process.
Taiwan Pat. No. M323183 discloses the casing of a laptop computer made with ceramic metal. The casing of the computer is divided into a bottom metallic layer, a pattern section and a coating layer. These three units are integrated to form a laptop computer casing which can prevent scratch marks as well as corrosion, and which can also be easily cleaned. However, this method diminishes the texture and the sheen of the metallic areas.
Therefore, an improved device and a method thereof for producing a pattern are desired to overcome the above-mentioned shortcomings.